Spirometry is a common pulmonary function test for measuring lung function. Specifically, spirometry is the measurement of the amount (volume) and/or speed (flow) of air that is inspired (inhaled) and/or expired (exhaled). Spirometry is an important technique in disease management for bronchial asthma and chronic obstructive pulmonary disease and other respiratory disorders.
The peak expiratory flow (PEF) is an example of a spirometric value being indicative of a person's maximum expiration flow rate. This value is typically measured with a peak flow meter, a small, hand-held device used to monitor a person's ability to breathe out air. The peak flow meter measures the degree of obstruction in the airways.